Since 2023 an autónomo's (self-employed person's) contribution depends on what you earn, but while you work nobody knows what you will earn that year. So each month's contribution is provisional and the following year it is adjusted to your real figures: that adjustment is the regularización. Here is how it works under the law, when it arrives and what to do if you have to pay or if you get money back. The whole system, from registration to your first invoice, is in how to register as an autónomo in Spain.
The amounts in the examples are the 2026 ones, the year that will be adjusted from 2027.
What the adjustment is
When you register you choose a contribution base (base de cotización) according to the net earnings you expect each month. That base and any you choose later are provisional (article 308.1.a, rule 6, of the General Social Security Law, Ley General de la Seguridad Social). Once Hacienda (the tax agency) knows your earnings for the year, it reports them to Social Security, which sets your final base and compares it with what you paid (article 308.1.c). Real Decreto-ley 13/2022 created this system for contributions from 01/01/2023. The detailed calculation is in article 46 of the contributions regulation, Real Decreto 2064/1995.
Which earnings count
Social Security does not look at what you invoice but at your countable earnings (rendimientos computables) (article 308.1.c, rules 1 and 2):
- Start from your business net income as calculated under IRPF (personal income tax) rules: income minus deductible expenses. Under direct assessment (estimación directa) the autónomo contributions you paid are added back, because you deducted them as an expense for IRPF.
- Add all your self-employed activities, including those you carry out as a partner or member of any entity.
- Take off 7% for generic expenses. If you are a director or controlling shareholder of a company, the deduction is 3%.
- Turn the result into a monthly average: divide it by the days you were registered in the year and multiply by 30 (article 44.2.a of Real Decreto 2064/1995).
That monthly average tells you which bracket (tramo) of the table you are in. If you are the director of your own company, your salary and, depending on your stake, its dividends also count: we explain it in what an autónomo societario is.
How it decides whether you pay or get a refund
Social Security works out the average of the provisional bases you paid on during the year and compares it with the bracket your earnings put you in (article 46.2 of Real Decreto 2064/1995). There are three possible outcomes:
- Your average base is inside your bracket, between its minimum and maximum base: there is no adjustment and your contributions become final.
- Your average base is below your bracket's minimum: your final base becomes that minimum and you pay the difference.
- Your average base is above your bracket's maximum: your final base becomes that maximum and you get the difference back.
Note the last case. If you overpaid, the refund takes you down to your bracket's maximum base, not its minimum. Each bracket has a range and within it the law accepts the base you chose.
The differences are charged at the contribution rates of the months being adjusted (rule 7 of the same article). In 2026 they add up to 31,5%: 28,3% for common contingencies, 1,3% for occupational contingencies, 0,9% for cese de actividad (the self-employed unemployment cover), 0,1% for vocational training and 0,9% for the intergenerational equity mechanism (articles 18 and 37 of Orden PJC/297/2026).
Two examples with the 2026 table
In 2026 the 2025 tables still apply under article 3.4 of Real Decreto-ley 3/2026 and Orden PJC/297/2026 sets them out in its article 18.1. The full table is in Social Security contributions for autónomos.
When you have to pay
Imagine you were registered all of 2026 and paid each month on €960,78, the minimum base of general brackets 2 and 3. You paid €302,65 a month, €3.631,80 for the year. Your IRPF net business income was €24.000.
- Countable earnings: €24.000 + €3.631,80 of contributions = €27.631,80.
- Minus 7% (€1.934,23): €25.697,57.
- Monthly average: €25.697,57 ÷ 365 × 30 = €2.112,13. You are in general bracket 6, which runs from €2.030 to €2.330.
- That bracket's minimum base is €1.274,51. You paid on €313,73 less each month.
- To pay: €313,73 × 12 months × 31,5% = €1.185,90.
When you get a refund
Now the opposite case. You paid all year on €1.274,51 but your countable earnings, after the 7%, were €13.380. Your monthly average is €1.099,73, which puts you in bracket 3 of the reduced table, whose maximum base is €1.166,70. You paid €107,81 a month above that maximum, so you get back €107,81 × 12 × 31,5% = €407,52.
When it arrives and your deadlines
Everything starts from your income tax return: Hacienda reports each year's earnings to Social Security from the following year onwards (article 308.1.c). Since a year's return is filed in the spring campaign of the next year, the adjustment arrives after that campaign. The law sets no specific date for the notice.
- If you have to pay, you have until the last day of the month after the one in which you are notified. If you pay within that period there is no surcharge or interest (article 308.1.c, rule 4). You pay with the payment document the Social Security Treasury (Tesorería General de la Seguridad Social) includes in the notice or makes available online (article 46.2, rule 5, of Real Decreto 2064/1995). If you do not pay in time, the debt is claimed through the ordinary procedure, with surcharges and interest.
- If you get a refund, the Treasury pays it on its own initiative, without you asking and without interest, before 30 April of the year after the one in which Hacienda reported your earnings. If they are reported in 2027, the refund arrives before 30/04/2028.
Two details from the same rule 4: surcharges and interest you already paid are never refunded. Contributions you failed to pay on time are still owed even if the adjustment goes in your favour.
What is not adjusted
- The tarifa plana (reduced flat rate for new autónomos). The first 12 months of reduced contribution are not adjusted even if you earn more than expected (article 38 ter.6 of Ley 20/2007). Nor are the 12 months of the extension, unless your earnings that year exceed the minimum wage (salario mínimo interprofesional). The details are in what the tarifa plana is and how to apply.
- Months of a late or ex officio registration, which are charged on the minimum base of bracket 1 of the general table (article 44.3.c and d of Real Decreto 2064/1995).
- Bases already used to calculate a benefit granted before the adjustment. The same goes for the bases of months in which you received a benefit (article 46.1). Those bases become final and the benefit is not recalculated.
If you do not file your income tax return
If you do not file your IRPF return or file it without declaring income while under direct assessment, your final base is the minimum base of group 7 of the general employee scheme (article 308.1.c, rule 5). In 2026 that is €1.424,40 a month (article 3 of Orden PJC/297/2026), more than the minimum base of the first ten brackets. Filing your return, even if you earn little, protects you from that base. How to do it is in the autónomo income tax return.
If Hacienda corrects your earnings later
If Hacienda later changes your earnings, after a review or because you file a correction, the adjustment can be revisited (article 308.1.c, rule 6). If they go down, you can ask for a refund of what you overpaid. If they go up, Hacienda reports it to Social Security and to the Labour Inspectorate, which decides whether to claim the difference.
How to avoid a large adjustment
The law does not just let you change your base during the year: it says you must do so to keep your contributions in line with what you expect to earn (article 308.1.a, rule 3). You get six chances a year and each change applies from the first day of the next two-month period. We cover it in how to change your autónomo contribution base. Because the adjustment looks at the yearly average, raising your base in time for the remaining months can leave you inside your bracket with nothing to pay.
For that you need to know what you have earned so far. In Facturaz your invoices and expenses become your modelo 303 and modelo 130 every quarter, so your net income for the year is in view before the letter arrives. With Autónomo Go (€24 + IVA a month) you file the returns yourself with everything prepared. With Autónomo Plus (€44 + IVA a month) our team files them. Both plans come with a 14-day free trial on pricing for autónomos.
